Transformerless mic to record DSL5cr amp with

[PelliX]

So the easiest temporary solution is to use my Orange cab for now as all I'd need is a speaker extension adapter.

No need for a special adapter, just a speaker lead. Unplug the built-in speaker, plug in the cab, done. Observe the impedence, of course.

Whilst the amp is being repaired (dud preamp and output tube) he may find a ground loop issue after all.

Repaired? That's a plug and play operation...?

 

[Emenius Sleepus]

No need for a special adapter, just a speaker lead. Unplug the built-in speaker, plug in the cab, done. Observe the impedence, of course.



Repaired? That's a plug and play operation...?

It won't reach an external cab as the cable is too short. So I need an extension.

I wanted to know if there was anything else wrong with the amp aside from the tubes going out

 

[PelliX]

It won't reach an external cab as the cable is too short. So I need an extension.

Skip the extension; just make or buy a 2m speaker lead. Should be long enough for most use cases with that amp. The lead used for the built-in speaker is jack to spade connectors - you want jack to jack, anyway. Regular mains flex would do perfectly here if you're out to save a few bob.

 

[Emenius Sleepus]

Unless I'm mistaken its the cable going from the power amp inside needs go into the cab and its not long enough. I can't just plug a regular speaker cable into that red speaker port and then out to another cab

 

[PelliX]

Unless I'm mistaken its the cable going from the power amp inside needs go into the cab and its not long enough.

You are mistaken...

I can't just plug a regular speaker cable into that red speaker port and then out to another cab

Yes, that's exactly how it works. Here's a picture of a DSL20CR, but the concept is identical:

The speaker lead is simply a male jack to two female spade connectors. You want to unplug that lead at the 'jack' or 'amp' end. Then plug in a regular jack to jack speaker lead between that red output and your cab.

 

[Emenius Sleepus]

Oh wait so that red ring input is like the back of an amp head that you run to a cab? Out of curiosity I just took the back panel off to see where the other end of the cable connected to. Its wired to the internal speaker.

 

[PelliX]

Oh wait so that red ring input is like the back of an amp head that you run to a cab?

Yup, where it says "Connect Speakers". That's the speaker output of the amp. On the 20CR above you see that the amp in question has mutiple taps whereas yours only has the one. Same concept, though.

Consider that many amps are produced in head and combo editions, like the 20CR (or 20HR head). They use the same chassis and so on, just a different wooden shell and the chassis is upside down in a combo. Same thing, really.

 

[Emenius Sleepus]

Oh I get it now sorry I was confusing myself back when I used the Marshall power amp to power a cab from a Kemper and that's the connection I was referring to. I have a DSL1cr too and already have a speaker cable so will give this a little test with my Orange 1x12 and my SM57

 

[Emenius Sleepus]

Just done a couple of tests with the internal and Orange speaker cab. I mic'd both up and did some test recordings and didn't find much hum with either the DSL1cr stock or the Orange 1x12. Had to use a fair bit of interface preamp gain but still relatively quiet. Strange.
So it may be something in the 5 watt amp that's making that loud hum.

 

[PelliX]

Just done a couple of tests with the internal and Orange speaker cab. I mic'd both up and did some test recordings and didn't find much hum with either the DSL1cr stock or the Orange 1x12. Had to use a fair bit of interface preamp gain but still relatively quiet. Strange.
So it may be something in the 5 watt amp that's making that loud hum.

As I suggested, it sounds more like the amp is at fault than anything else. Also, while the 57 is not exactly a very high output mic, how quiet is this? Those Focusrites have a fair deal of gain. You don't happen to have PAD (20dB padding) enabled or anything like that?

Does the amp vibrate at all? Depending on the stand, floor, table, whatever vibration can be transferred to a mic. My JTM for example vibrates a little bit when on, caused by the power transformer.

 

[Emenius Sleepus]

As I suggested, it sounds more like the amp is at fault than anything else. Also, while the 57 is not exactly a very high output mic, how quiet is this? Those Focusrites have a fair deal of gain. You don't happen to have PAD (20dB padding) enabled or anything like that?

Does the amp vibrate at all? Depending on the stand, floor, table, whatever vibration can be transferred to a mic. My JTM for example vibrates a little bit when on, caused by the power transformer.

Yeah cos I've tested with 2 different cabs now. The amp wasn't turned up very loud, preamp gain around 3pm so 3/4 of the way up. No padding enabled.

No the amp was sitting on the top of the cabinet so no vibrating. I think if I did record the 5 watt in the future I'd probably prefer the Orange cab speaker so once I get that back with the new tubes I will definitely test it the same way as I did today. Seems strange how one speaker can react with louder humming.

 

[guitarbilly74]

The mic is connected to my Scarlett 8i6. But like previously mentioned I've recorded my Orange cabs (got a 1x12 and a 4x12) and neither hum so it can't be the 57.

That's exactly what I was saying. Unless the 57 is broken (and you tested it and said it's not), the problem is NOT the 57. It has to be something else in the signal chain or a grounding issue.

 

[PelliX]

That's exactly what I was saying. Unless the 57 is broken (and you tested it and said it's not), the problem is NOT the 57. It has to be something else in the signal chain or a grounding issue.

Given that the hum changes depending on the position of the mic against the speaker in the combo, I'm guessing the amp is blasting a significant magnetic field or the amp is humming - as most do a little - and because of the whisper level recordings, it shows up. I never worry about hum, I just point at the bass player and people seem happy with that...

 

[ElvisNixon]

Given that the hum changes depending on the position of the mic against the speaker in the combo, I'm guessing the amp is blasting a significant magnetic field or the amp is humming - as most do a little - and because of the whisper level recordings, it shows up. I never worry about hum, I just point at the bass player and people seem happy with that...

All very good points throughout this thread. I would agree with everything @PelliX has said.

It’s some sort of parasitic noise that’s entering your signal chain somewhere. There’s two types of common noise issues. One is called electromagnetic interference or EMI and the other is radio frequency interference or RFI.

Both types can be caused by the environment you’re recording in. Things like dimmers, fluorescent lights, ceiling fans, a crappy or damaged USB cable, hard drives, garage door openers, etc.

It sounds like you have quite a few things in your signal path. An Orange amp, a Kemper, a power amp,etc. You need to troubleshoot the whole signal chain and make sure that your Focusrite interface is set up correctly and isn’t set on “line in” when it should be set to microphone level input. The level and impedance mismatches can cause noise problems.

You’re going to be chasing your tail unless you unplug everything temporarily and start with the Orange amp by itself and trace a path back until you get to the interface. Like I said, eliminate all sources of EMI and RFI first. make sure your cables including computer cables are in good condition and haven’t been damaged.

The chance that it’s the SM57 is minimal compared to everything else you need to check. You can literally hammer nails with a 57 and it will be okay. I still have several from the early 90’s that have been ridden hard and put away wet. You mentioned that you have two 57’s? The chances that BOTH are faulty is near zero. In the last several years there have been boxes like the Cloudlifter that will let you set your inputs on your interface lower and changes the impedance and such. They are strictly optional though.

You’re going to have to use the process of elimination to troubleshoot your whole signal chain. Start simple and methodical. Connect each component of your signal chain one at a time and also be aware of environmental noise like RMI and RFI. Second only to ground loops, they are the cause of most of the maddening noise which may be hard to find in a complex signal chain.

Good luck and take it slow and methodically.

 

[Emenius Sleepus]

Oh yeah shit, I was recording earlier clips with the line input instead of mic but I was in a bit of a hurry. Sometimes I forget to stich inputs on the interface.

I will also add the humming is most prominent when plugged into a mixer as I was recording live clips with another guitarist (I come out the main output of the Kemper and he goes out the DSL5CR via the SM57). Pre amp gain is around noon so pretty high.

Also I do have a cloudlifter and have used that to record into Reaper DAW and its caused a bit of humming as well despite not having to turn the preamp gain up as high.

 

[PelliX]

Oh yeah shit, I was recording earlier clips with the line input instead of mic but I was in a bit of a hurry. Sometimes I forget to stich inputs on the interface.

The line inputs are jacks, the mic inputs are XLR. Unless you got an XLR-jack cable in there somehow, it shouldn't matter. A few of the smaller Focusrite interfaces (Solo, 2i2, I think) had a silly issue where selecting Line or Instrument levels would actually affect the mic preamp. I don't think the bigger ones ever suffered from that.

I will also add the humming is most prominent when plugged into a mixer as I was recording live clips with another guitarist (I come out the main output of the Kemper and he goes out the DSL5CR via the SM57). Pre amp gain is around noon so pretty high.

Right, so you're plugging into the Kemper which feeds into the mixer. Are you recording that part at all?

The other guitarist is plugging in to the DSL which is mic'ed through the mixer... and you run the main/control room outputs to the interface? Then Line level would be correct. It would help to clarify the setup, maybe. Also note that when you're using mixers, they tend to become a central ground for attached gear, often.

Also I do have a cloudlifter and have used that to record into Reaper DAW and its caused a bit of humming as well despite not having to turn the preamp gain up as high.

While I don't have one, that sounds weird. Do you have phantom power enabled for the mic input all the time? The Cloudlifter requires it, the 57 alone does not.

 

[Emenius Sleepus]

The line inputs are jacks, the mic inputs are XLR. Unless you got an XLR-jack cable in there somehow, it shouldn't matter. A few of the smaller Focusrite interfaces (Solo, 2i2, I think) had a silly issue where selecting Line or Instrument levels would actually affect the mic preamp. I don't think the bigger ones ever suffered from that.



Right, so you're plugging into the Kemper which feeds into the mixer. Are you recording that part at all?

The other guitarist is plugging in to the DSL which is mic'ed through the mixer... and you run the main/control room outputs to the interface? Then Line level would be correct. It would help to clarify the setup, maybe. Also note that when you're using mixers, they tend to become a central ground for attached gear, often.



While I don't have one, that sounds weird. Do you have phantom power enabled for the mic input all the time? The Cloudlifter requires it, the 57 alone does not.

Nah its xlr - xlr so it would pick it up as a mic level input anyway wouldn't it?

Yes this was an old way of recording videos of us jamming to songs we like, since about a year ago I changed it and now record all audio into a DAW first and then film the video after and then sync together. But I still experience the humming regardless with the DSL5cr.

For recording audio only then I take the mixer out the chain of course.

Yes phantom power for the cloudlifter, I've used it to record into Reaper as I cranking the 8i6 pre amp gain to almost full to get a useable signal.

 

[PelliX]

Nah its xlr - xlr so it would pick it up as a mic level input anyway wouldn't it?

Should do, yes. Check if the switch makes any difference - it shouldn't.

Yes phantom power for the cloudlifter, I've used it to record into Reaper as I cranking the 8i6 pre amp gain to almost full to get a useable signal.

There's something wrong there, and I'd almost say it smells a bit like cables somehow. A 57 with a Cloudlifter through an 8i6 mic preamp should result in a pretty hot signal. The Cloudlifter will isolate the downstream mic from any phantom power, but if you're plugging the mic straight in, best to keep it off. It won't hurt the 57 (neither will a car rolling over it or a medium sized nuclear explosion), but it can cause odd issues.

Here's an idea, does the mixer have mic inputs? Have you tried plugging a 57 into that and checking if you get any hum? If not, then run the main/master/monitor/channel/whatever outputs to the interface and record some. Any hum in the recording? Note that you should of course use the jack inputs at Line level for that on the Scarlett.

 

[guitarbilly74]

Yeah it could be just gain staging too. If you're setting the amp volume way too low and cranking the interface's input volume that could cause hum. Maybe turn the amp up a bit and lower the gain on the interface. You can throw a blanket on top of the amp and mic if you need a bit less volume in the room, have the amp facing a different direction or even set the amp up in a different room.

I will also add the humming is most prominent when plugged into a mixer as I was recording live clips with another guitarist (I come out the main output of the Kemper and he goes out the DSL5CR via the SM57). Pre amp gain is around noon so pretty high.

This could indicate a ground loop between the amp and mixer and possibly even the interface. Try to do a ground lift on the mixer or at least on the channel the mic is plugged in. An isolation transformer between the amp and mixer could possibly help too.

 

[guitarbilly74]

I have a Cloudlifter that I use with my SM7B when recording speech level voice with it. Never had a problem with hum with it.

But anyway, A SM57 should not need a Cloudlifter, specially when recording a guitar amp.